PATHOGENESIS OF ALOPECIA 497 Figure 28.--1 year later. This was observed in approximately 5 per cent of the patients treated by local steroid injections. Mild tissue loss did not seem to interfere with hair growth. The discomforts caused by the injections, the prick of the needle and a burning sensation, were controlled by preparatory freezing with ethyl chlo- ride. The swelling associated with large-volume injections was treated by pressure or by the addition of hyaluronidase to the suspensions. The regrowing hair grossly showed the same texture and pigmentation as the patient's normal hair. Occasionally a patient, usually with alopecia totalis, would claim that the new hair was darker and curlier than his normal hair. Tattooing as a method of applying steroids locally has been used but is not satisfactory because of the trauma produced by the hundreds of punctures necessary to administer sufficient amounts of steroid. Application of steroids by inunction and iontophoresis failed to produce hair regrowth. In alopecia areata the hair regrowth that occurs spontaneously may be gray. With repeated episodes a mixture of gray and pigmented hair develop. The pi•maqented hair is sometimes more susceptible to loss during recurrences. Occasionally all the pigmented hair is suddenly lost and the patient therefore appears rapidly to have become completely gray, when actually he has suddenly become partially and selectively bald. dlopecia mucinosa is a rare, only recently recognized variety of non- cicartical alopecia of unknown etiology.

498 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 29.--Male-pattern alopecia--the arrow indicates the site of a graft taken from a hair growing area in the posterior scalp. Two years ago, this had been implanted at the edge of the receding hairline (dotted line). Note receded hairline. Graft continues to grow hair. .. .. Figure 30.•Male-pattern alopecia with hair growth from grafts 4 years after transplantation. Right frontal scalp used as control.